DD4 is identical with human chlordecone reductase and 3alpha-hydroxysteroid dehydrogenase type 1, EC 1.1.1.213, catalyzes the oxidoreduction of various 3alpha-hydroxysteroids including bile acids and belong to the aldo-keto reductase superfamily, in this concern termed AKR1C4

dihydrodiol dehydrogenase catalyzes the NADP+-linked oxidation of dihydrodiols of aromatic hydrocarbons to their corresponding catechols and is regarded as a toxication enzyme in the metabolism of carcinogenic polycyclic aromatic hydrocarbons because oxidation by the enzyme yields reactive and redox-active ortho-quinones and reactive oxygen species, broad substrate specificity indicates additional roles of the enzyme in the metabolism of endogenous and xenobiotic carbonyl compounds and the prevention of the development of glycation

dimeric dihydrodiol dehydrogenase catalyses the nicotinamide adenine dinucleotide phosphate NADP+-dependent oxidation of trans-dihydrodiols of aromatic hydrocarbons to their corresponding catechols, dimeric dihydrodiol dehydrogenase is also competent in the NADPH-driven reduction of a limited number of aldehyde and dicarbonyl compounds such as 3-deoxyglucosone, camphorquinone, and 3-nitrobenzaldehyde

monomeric forms are identical with 3alpha-hydroxysteroid dehydrogenase EC 1.1.1.50 and provide a broad substrate specificity, while dimeric forms are identical with D-xylose dehydrogenase EC 1.1.1.179 and are active with trans-dihydrodiols and dicarbonyl compounds

F2: high activity towards naphthalene dihydrodiol and some alcohols, low activity towards trans- and cis-benzene dihydrodiols and some alcohols, reduction of aldoses, vicinal diketones, aromatic aldehydes and glyceraldehydes with NADPH or NADH as cofactors

dihydrodiol dehydrogenase catalyzes the NADP+-linked oxidation of dihydrodiols of aromatic hydrocarbons to their corresponding catechols and is regarded as a toxication enzyme in the metabolism of carcinogenic polycyclic aromatic hydrocarbons because oxidation by the enzyme yields reactive and redox-active ortho-quinones and reactive oxygen species, broad substrate specificity indicates additional roles of the enzyme in the metabolism of endogenous and xenobiotic carbonyl compounds and the prevention of the development of glycation

dimeric dihydrodiol dehydrogenase catalyses the nicotinamide adenine dinucleotide phosphate NADP+-dependent oxidation of trans-dihydrodiols of aromatic hydrocarbons to their corresponding catechols, dimeric dihydrodiol dehydrogenase is also competent in the NADPH-driven reduction of a limited number of aldehyde and dicarbonyl compounds such as 3-deoxyglucosone, camphorquinone, and 3-nitrobenzaldehyde

the hydroxyl group of 4-hydroxyacetophenone forms hydrogen bond interactions with the side-chain oxygen and the main chain nitrogen of Asp280, the benzene ring and methyl group make a number of hydrophobic contacts with Phe279, Leu158 and Leu177

crystals are obtained at 19.9°C in a culture plate via the vapour-diffusion method, crystal structure of dimeric dihydrodiol dehydrogenase complexed with the inhibitor isoascorbic acid is determined at 2.59 A resolution

recombinant enzymes are purified from the 12000g supernatants of the homogenates of the cells, the single mutant enzymes are partially purified by the ammonium sulphate fractionation and chromatography on a Sephadex G-100 column, the wild type and double mutant enzyme are further purified by chromatography on a Red Sepharose column